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Science

Giant Black Hole Found 283

Posted by chrisd from the infinite-radius-finite-diameter dept.
paradox writes "Reuters is reporting that scientists have found a massive black hole 40,000 light-years away that could change the way scientists think about black holes. The mass of this particular black hole is 14 times the mass of the sun, compared to the typical mass of 3 to 7 suns."
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Giant Black Hole Found More

Giant Black Hole Found

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  • Scientists should really... (Score:3, Offtopic)

    by tcd004 ( 134130 ) on Wednesday November 28, 2001 @08:53PM (#2628283) Homepage
    Scientists should really leave rosie o'donnell alone.

    tcd004
  • Destroy it before it kills us all!

  • Why the puzzle? (Score:1, Interesting)

    by Mt._Honkey ( 514673 )
    Is it so odd that a stelar black hole formed, and maybe driften near a cluster of stars or a big ass nebula in its lifetime? Maybe it's ancient.
  • But what about its physical size? I mean, when you are dealing with monstrous astro-physical phenoms beyond human comprehension, isn't it important to be boggled by the density?

    • Re:Size IS important. (Score:5, Informative)

      by zCyl ( 14362 ) on Wednesday November 28, 2001 @09:07PM (#2628362)
      But what about its physical size? I mean, when you are dealing with monstrous astro-physical phenoms beyond human comprehension, isn't it important to be boggled by the density?

      Because there IS no size. A black hole by definition is a singularity, and has no conceivable dimensions. The closest thing a black hole has to a size is what's called the Schwarzschild radius, or the event horizon. This radius is the distance from the center at which light can no longer escape (ignoring Hawking radiation, another topic entirely). The Schwarzschild radius is equal to 2GM/c^2, where G is the gravitational constant, c is the speed of light, and M is the mass of the black hole. So the radius is really nothing more than a constant times the mass.

      If you know the mass, and you don't have rotation, you know everything that can be known about it.
      • I beleive you can know the charge also, positve or negative.

      • Re:Size IS important. (Score:5, Informative)

        by the_2nd_coming ( 444906 ) on Wednesday November 28, 2001 @09:31PM (#2628468) Homepage
        no a sigularity is the center of a black hole, it is where space time becomes undefind. a black hole is the defined by the eventhorizon. so it does have a size. if it is just a sigularity it is not a black hole, it is a naked sigularity.

      • Re:Size IS important. (Score:2, Interesting)

        by anethema ( 99553 )
        I'm confused. I was under the impression that a black hole was a star that had collapsed and the space between the electrons and the nucleus (sp?) was reduced to zero. We're always told if the earth turned into a black hole, (yes i know it cant) it would be the size of a basketball. Can someone please clarify? Im giving up the right to moderate on this story by posting this, so someone better reply :) ...
    • If it's a black hole, its density is infinite. Its physical size is zero, unless you mean the size to its event horizon, but the actual mass is all at the center.
    • A black hole is a singularity. It has no size, and therefore its density is infinite.

      The sphere defined by its event horizon does have a size, but it will be very small (a few tens of miles across, perhaps). Maybe an astrophysicist in the audience will compute the size for us?
      • Let's see. I found the radius of the event horizon to be about 41.8 Km. That's pretty darn huge. The formula I used was 2GM/c^2. Based on the data that the mass is about 14 Solar masses, M is roughly equal to 2.8e31.

      • Re:Size IS important. (Score:5, Informative)

        by sigwinch ( 115375 ) on Wednesday November 28, 2001 @11:09PM (#2628968) Homepage
        A black hole is a singularity.
        It's important to remember that a singularity is a mathematical artifact where a physical property has no meaningful definition when measured by a particular metric. For instance, the north pole of the Earth is a longitude singularity, a point where the very concept of longitude ceases to have physical meaning.
        It has no size, and therefore its density is infinite.
        Actually, that turns out not to be the case, at least not relative to our reference frame. Imagine you're a distant (and indestructible!) observer watching a star collapse into a black hole. The more it collapses, the more it is affected by gravitational time dilation: time appears to run slower for the matter in the star than for the observer. Clocks in the star slow down. Light travelling away from the star is shifted towards the red end of the spectrum.

        The more the star shrinks, the more it is affected by gravitational time dilation, and thus the more slowly it collapses as measured by the outside observer. The collapse thus asymptotically approaches infinite time dilation, and appears to freeze in time to the distant observer. Its physical size at the asymptote is the size of the event horizon, a.k.a. the Schwarzchild radius.

        One way of measuring the star is to ask how long it would take light to travel from its outside edge to its center, as measured by a distant observer. (Theoretically, of course, as the star would absorb any light.) Think of it as the radius measured in units of literal light years. As the collapse approaches infinite time dilation, the 'light radius' approaches infinity. This is the singularity at the center of the black hole, and is a mathematical construct arising from the distant observer's point of view. It does not mean that density or any local physical parameter is infinite

        I'm deliberately ignoring what the collapse looks like to an observer inside the star. Known physics simply cannot make any meaningful predictions, except that it will never be observable from the outside (because it literally takes an eternity to occur).

    • Re:Size IS important. (Score:5, Informative)

      by cascino ( 454769 ) on Wednesday November 28, 2001 @09:23PM (#2628427) Homepage
      Technically the singularity itself possesses infinte density, and thus it's size cannot be resolved (i.e.: it's a single point, no matter how close you magnify it).
      The Schwarzschild radius of such an object, however (better known as the "event horizon"), can be calculated fairly simply using a variation of the escape velocity formula
      Rs = 2*G*M / c^2
      Where G is the gravitational constant, M is the mass of the object, and c is the speed of light.
      Plugging the numbers into the equation yields a radius of 2.95 * 10^6 km. Therefore this black hole has a radius just over four times the size of the sun, and an area 16 times as large. Compared to black holes usually on scales relative to that of the Earth, that's REAL big.

  • oh, NO! (Score:3, Funny)

    by A_Non_Moose ( 413034 ) on Wednesday November 28, 2001 @08:58PM (#2628310) Homepage Journal
    First a hole in wu-ftpd and now they are in space!

    Hey, that is it, a black hole is a security exploit in space.

    Maximillian!!!!

  • Repeated story (Score:3, Funny)

    by rjamestaylor ( 117847 ) <rjamestaylor@gmail.com> on Wednesday November 28, 2001 @08:59PM (#2628320) Journal
    Michael just posted a story [slashdot.org] about the discovery of a giant hole....

    (it's funny. laugh.)

  • Another hole found? (Score:3, Offtopic)

    by Anonymous Coward on Wednesday November 28, 2001 @09:02PM (#2628335)
    Specialists concur that this is hole is even bigger than the previous hole found (and also reported on /., one story back).

    Although CERN tried to keep this hole silent until every God had a patch available to stuff the hole, it didn't work out that way.

  • It will change the way scientists think about them (Score:4, Funny)

    by glwtta ( 532858 ) on Wednesday November 28, 2001 @09:05PM (#2628350) Homepage
    "We now think they are bigger!"

  • Distance (Score:5, Insightful)

    by gandalf_grey ( 93942 ) on Wednesday November 28, 2001 @09:07PM (#2628360) Homepage
    It's worth noting that the center of the galaxy is 26,000 lightyears from us, see: space.com [space.com]. So 40,000 LY is not exactly nearby, as the story seems to imply.

    So, don't worry about being sucked into infinitely long strings of goo just yet.

  • I've always had doubts... (Score:3, Insightful)

    by fireboy1919 ( 257783 ) <{rustyp} {at} {freeshell.org}> on Wednesday November 28, 2001 @09:07PM (#2628361) Homepage Journal
    ...about extrapolated data.

    How do we find stars and planets? We make assumptions about stellar phenomena and then predict other phenomena using those assumptions as long as they seem to work.

    We do the same thing with everything we use. We've done the same thing with other stuff, but most of the time, we can observe a lot more dimensions of the data than we can with stellar phenomenon to make our predictions.

    So I suggest that there are any number of reasons that could indicate why this answer makes sense: the model for detecting mass may be wrong, or the model of the formation of black holse, or somethinig else that I haven't considered.

    At any rate, we have a long way to go to learn to understand stellar phenomena.

    • Re:I've always had doubts... (Score:4, Insightful)

      by LMCBoy ( 185365 ) on Thursday November 29, 2001 @09:08AM (#2630454) Homepage Journal
      "How do we find stars and planets? We make assumptions about stellar phenomena and then predict other phenomena using those assumptions as long as they seem to work."

      Huh? We find stars and planets by stepping outside at night and looking up. What exactly are the "stellar phenomena" that we have a long way to go before understanding?

      I suppose, since you're questioning the mass determination of the black hole, you must be saying that we don't yet understand Kepler's 3rd law of motion (that is the only theory needed for the measurement). Hmm...Kepler came up with that in 1609. In 400 years, his laws have been used to: construct the first accurate mathematical model of the solar system (still in use today), predict a planet beyond Uranus (Neptune was discovered exactly where Keplerian physics said it had to be), send humans to the moon, send probes to the outer planets and beyond, and determine masses of binary stars throughout our galaxy.

      In short, there's nothing in this particular measurement that requires *any* understanding of stellar physics. It's a simple application of 400-year old Newtonian gravity. If you want to question the result, I suggest looking at the systematic errors of the observations (e.g., is the inclination angle of the system known? if not, the black hole could be more massive than measured).

      Oh, and the process you describe (start with an assumption, make a prediction based on the assumption, test prediction by experiment/observation, refine assumption) is called the scientific method, not "extrapolating data".

  • Irresponsible (Score:5, Funny)

    by Puk ( 80503 ) on Wednesday November 28, 2001 @09:13PM (#2628386)
    I think Reuters is being completely irresponsible by reporting this hole before a fix can be completed by all affected parties. The only current known fix for this hole is to make sure less matter falls in than energy is radiated by the hole, and keep it that way for a long time. In the meantime (however many millions and millions of years that takes), script kiddies with FTL drive capabilities will be having a field day.

    Slashdot is just contributing to the problem by spreading the news. Sheesh!

    -Puk

    p.s. This hole is hardly a surprise. We've found that space is riddled with such holes, and to my knowledge, none of them have been closed. If space was open source to begin with, enterprising hackers would have found these holes long ago, and plugged them with Bill Gates' ego.
  • Ignoring all the obvious jokes that ACs are going to post...

    14xSun is no big deal. The hypothetical central black hole in each galaxy has been ranged from 100-100,000 xSun mass, 10k being a nice round figure.

    Also, considering that modern theory says that a sun needs to be anywhere from 10x to 100x our sun's mass, even considering the mass blown off during contraction, 7x sun mass is just a wrong number. 14x would be somewhere along the minimum mass to generate a black hole.

    Of course, if worldwide consensus has now switched in the last 12 hours, everything above I said is wrong. Cold fusion, anyone?

    • Re:Some info (Score:4, Informative)

      by JoeRobe ( 207552 ) on Wednesday November 28, 2001 @10:06PM (#2628634) Homepage
      14x is a big deal. The 100-100000 solar mass black holes at the center of galaxies (which still isn't proven, but has a lot of data pointing towards it) are not stellar black holes. They would be called galactic black holes. Stellar black holes are byproducts of dead stars. The Chandra limit, 1.4 solar masses, is the minimum mass that is needed to make stellar remnants collapse. If it is over 2 or 3 solar masses, then it collapses all the way into a black hole. Now, that was figured out several decades ago, so of course that number might be slightly "off," but I seriously doubt that Chandra was off by a factor of 10. I'm curious where you get 10-100 solar masses from...

      When a star with a mass of ~30 solar masses or higher dies, it supernovas, blowing off most of its mass. IF WHAT'S LEFT is greater than a couple of solar masses (and within the Schwarzschild radius), then it collapses into a black hole. I repeat: it MUST ONLY be more massive than a few (2 or 3 - it's under debate) solar masses! True, the original star must be greater than ~30 solar masses; but the mass of the black hole is far less than the mass of the original star. THIS is why a 14 solar mass black hole is so strange!

      By the way, NO information regarding black holes is the subject of "worldwide consensus".
    • You're confusing two different masses. One is the mass of the star that collapses in a type-II supernova. There's a minimal size for such stars (just as there's a minimal size for a star to be a star, instead of a large Jovian body), and IIRC there's also a maximum mass due to various physical constraints.

      The other mass is what's crunched into the black hole. If I remember the numbers right, and they haven't been surplanted by more recent research, at "maximum" crunch some of the stellar mass is falling inward at a third of the speed of light, and the maximum density is something like 4 times that of a regular nucleus. This is a *very* hard surface, and anything outside of the maximum crunch will be blown outward. A lot of the matter in the crunch will be blown outward, as the "spring" releases. This is the same force (under Newton's second law) that pushes the matter within this shell inward past the final resisting force and into a black hole.

      All of this conspires to mean that only a fraction of the stellar mass will actually end up in the black hole. Far more will end up in the planetary nebula. But it all together and you get the usual figure of about 7 stellar masses as the maximum mass of a black hole created by a single star.

  • Supermassive black holes (Score:4, Interesting)

    by ukryule ( 186826 ) <slashdot AT yule DOT org> on Wednesday November 28, 2001 @09:24PM (#2628433) Homepage
    Whatever happened to the theory of supermassive black holes? [nasa.gov] These black holes, at the centre of each galaxy are supposed to be millions of times heavier than the sun.

    So what's so great about a black hole only 14 times as heavy as the sun (which is also further away than the centre of our galaxy)?
    • I don't see what's so confusing about it. This black hole was part of a binary system, with a star progressively feeding a black hole. It is an example of a relatively small phenomenon. Supermassive black holes, on the other hand, represent the cores of galaxies, and are incomparable to these "small" black holes for any number of reasons. This 14-sol black hole is new because we never knew small black holes could be so large.
  • black holes are not typicly 3 -7 suns in mass they are like 3-7 thousand suns in mass. a 14 sun mass black hole is very light.....I think it is spose to be 14000 suns......
  • GRS 1915+105 has been known about for quite a while actually. It was first seen as a strong x-ray source in the early 90's. http://www.ufoinfo.com/space/shockwaves.shtml is a great article giving info about this microquasar.
  • On the subject of black holes, it's interesting to note that our entire (known) universe could be inside of a black hole. In fact, that super-black hole could be inside of a larger universe, and so on ad infinadum, or as far as you wanted to observe. conversely, since we seem to always be finding that our current "elementary" particules are in fact made up of smaller stuff. (atoms -> protons&electrons etc. -> quarks -> strings), black holes in our universes could contain entire universes within them.

    Or perhaps, since the massive gravity of a blackhole would warp 4-dimensional spacetime, perhaps they lead to other unknown parts of this universe, so far away that we've never observed or discovered it. in that case, having a black hole nearby wouldn't be that bad. We'd still have to find some exotic matter or something to counteract the tidal forces, and there's time discrepancy issues to deal with, but that's a somewhat moot point.
    • ---On the subject of black holes, it's interesting to note that our entire (known) universe could be inside of a black hole.---

      This isn't really a good way to phrase it. "Inside" is not a concept that conveys any helpful meaning about this possibility, and in fact it sort of really confuses the issue. The basic physics point is this: it looks as if an entire universe can start from just a single singularity: that our universe could have started as a result of a quantum event. Victor Sternger has discussed this idea at length.

      ---We'd still have to find some exotic matter or something to counteract the tidal forces, and there's time discrepancy issues to deal with, but that's a somewhat moot point.---

      Moot because it doesn't seem in the least possible? This "matter" would have be so exotic that it would be unlike any "matter" that anyone has ever even concieved of before to survive the tidal forces.
    • "it's interesting to note that our entire (known) universe could be inside of a black hole."

      Wow, groovy.

      Except for the troubling lack of a singularity anywhere, and our complete failure to notice the tidal forces that should be ripping us all to shreds (how is that a "moot point"?)...
  • how do they work out the mass of a black hole?

    considering that they are so massive that the gravity causes it to be relitivly small, they can't work on size - so what do they work on?

    eh?

  • Stellar, middle-weight, supermassive (Score:5, Informative)

    by michaeldouma ( 311409 ) on Wednesday November 28, 2001 @09:37PM (#2628496) Homepage
    There are three main classes of black hole [nasa.gov]. This article relates to the "stellar" type...

    Astronomers suspect that most black holes are produced when massive stars (at least 8-10 times the Sun's mass) reach the end of their lifecycle. This is a so-called "stellar black hole." Stellar black holes [nasa.gov] are the remains of dead stars several times heavier than the Sun, compressed to a diameter of a few miles or less. Supermassive black holes [nasa.gov] have masses comparable to those of a typical galaxy. These masses range anywhere from a million to 100 billion of our Suns. Supermassive black holes tend to be in the centers of galaxies, creating what are called Active Galactic Nuclei (AGNs). They may have formed in the early universe from giant gas clouds or from the collapse of clusters of immense numbers of stars. Lastly, the field of black holes, formerly dominated by heavyweights packing the gravitational punch of a billion Suns and lightweights just a few times heavier than our Sun, has another contender, the middleweight [nasa.gov] black holes, weighing in at 100 to 10,000 Suns.

  • Gah! Who wrote that? It reads like a list of facts, looks like somone just forgot the &ltul&gt tags.

  • Those naive scientists (Score:3, Funny)

    by BillyGoatThree ( 324006 ) on Wednesday November 28, 2001 @09:38PM (#2628501)
    "Reuters is reporting that scientists have found a massive black hole..."

    Sounds like somebody should learn to hover over Slashdot links before clicking them...

  • oh man... (Score:4, Funny)

    by SaturnTim ( 445813 ) on Wednesday November 28, 2001 @09:46PM (#2628538) Homepage


    oh man, that sucks...

    (Black hole? Get it? Sucks? )

    man, i picked the wrong week to stop sniffing glue.

    --ST

  • article on the science journal nature, (Score:5, Informative)

    by vikool ( 523319 ) <vikas@pu[ ]e.edu ['rdu' in gap]> on Wednesday November 28, 2001 @10:14PM (#2628691)
    here is the article on the science journal nature, it is slightly more detailed than the one on reuters

    http://www.nature.com/nsu/011129/011129-13.html [nature.com]

    vikas

  • Stop the sun now! (Score:3, Funny)

    by piecewise ( 169377 ) on Wednesday November 28, 2001 @10:51PM (#2628886) Journal
    Come, fell Slashdotters! We must stop these scientists and our fellow readers for discussing extracting kinetic energy from black holes!

    Instead, we must focus on more realistic goals:

    1. Building giant solar structures on top of our homes!
    2. Trying to run our SUVs using corn!
    3. Convince ourselves that wind mills are actually doing anything for us!

    Come! Unite! Ignore the energy crisis and come up with silly ideas!

    Ooh, i forgot one.

    4. Believe that Americans might actually CONSERVE! Hhaahhaha!

    Sorry -- it's too bad being cynical didn't produce a significant amount of energy. ;-)
    • Sorry -- it's too bad being cynical didn't produce a significant amount of energy. ;-)

      if cynicism ever actually produced energy, America would actually look forward to elections and MS products! too much to hope for...
  • I remember reading in the literature about a survey of the masses of all known stellar-mass black holes, which led to the interesting discovery that, for reasons unknown, a majority of black holes mass about 7 Msun.

    I can't help but wonder if a 14 Msun black hole is the remnant of a black hole merger. Maybe we'll be able to compare the black-hole-merger-grand-challenge problem with reality after all.

  • 40,000 Light Years? (Score:3, Funny)

    by BoarderPhreak ( 234086 ) on Wednesday November 28, 2001 @11:35PM (#2629068)
    Would that be the Delta or Gamma quadrant? ;)

  • This is an amazing discovery. I'd like to know what kind of equipment and techniques scientists (or should I say astronomers) use to compute the mass of things such as black holes.

    In fact, I've always been interested in space, stars, planets and related subjects. If there was some software (inexpensive or even free) that allowed me to perform my own computations (perhaps using information on the net which is published by observatories or NASA or whatever), that would indeed be the coolest thing. I've searched for information like that, but I haven't found any, so I assume that space explorers down here on Earth don't make any of their information publicly available. It's a shame though.

    Of course, I know of programs that have maps of the stars and whatever, but there really isn't any information on things like blue/red shifts (as an example off the top of my head).

    Well all of this stuff probably requires supercomputers anyway, which is something I don't have.

    Oh well.

    • Actually, most of the data used by astronomers is publicly available. Try the following:

      HST data archive [stsci.edu]: every HST image. Also has other mission data.

      Astronomical Data Center [nasa.gov]: archive of data tables published in peer-review astronomy journals

      NASA/IPAC Extragalactic Database [caltech.edu]: index of known data for other galaxies. You can get redshifts here, for example.

      The software used by astronomers is also generally publicly available. For example, Debian Linux ships with IRAF, the image reduction software that most of us use (the ones who can't afford IDL anyway).
  • The owner of the black hole, 40,000 light years away has been sued by the RIAA because of distributing matter against the DMCA.

    DMCA 3, FREEDOM 0

    The owner of the black hole takes the charge not lightly and plans to close the black hole completely leaving space and time in it's destruction. GOD 1, DMCA 0

  • giant hole (Score:2, Funny)

    by ljoas ( 93259 )
    Ok!

    Who sent the goats.ex link to NASA?

    /L

  • initial report (Score:2, Informative)

    by vikool ( 523319 )
    this page gives the first report of an anomaly that came about on the GRS1915+105

    http://www.nature.com/doifinder/10.1038/35107019 [nature.com]

    vikas

  • ...and yet the biggest black hole competition is still left undecided. The final two contestants are "The Space Between Bush's Legs", and "The Vacum Between John 'beat by a dead guy" Ashcroft's ears".
  • The article mentions 3 to 7 suns begin the normal size of a black hole...

    This does not seem correct.

    I have been told that this would rather be described as a "pulsar".
    (Dr Evil made me do it! ;) )

    Anyhow, this is just my 0.02 worth of destructive critisism...
    :P
  • From the article:

    Black holes suck in everything near them including light...

    This is a very common misconception, judging by the number of otherwise well-informed Slashdot readers who have been repeating this fallacy. Black holes do not suck in things any more than the Earth or Sun do. The unusual gravitational effects of a black hole are only evident for bodies that are close to the event horizon.

    If the Sun was replaced by a black hole with the same mass, the planets and other bodies in the solar system would continue to orbit as if nothing unusual had happened. They would NOT be "sucked in".

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